Abstract Influenza is the cause of considerable morbidity and mortality globally. Certain groups, i.e., infants, pregnant young women, and older adults are especially at risk for severe disease. Despite immunization being the most effective and economical prophylactic approach, vaccines often provide less than optimal defense against an influenza illness, with efficacies ranging from 10-60%. This inadequate vaccine efficacy is mainly due to the high mutation rate (antigenic drift), or reassortment (antigenic shift) of the surface influenza molecule hemagglutinin (HA) which is the primary target of influenza vaccines. As a result, circulating influenza strains may evade the body?s protective antibodies induced by vaccination because the influenza?s targeted epitope may have mutated and no longer be recognized by the antibodies. The vast majority of influenza vaccine doses made today are produced in chicken eggs. This process takes 6-8 months which increases the probability of influenza mutation and the associated decreased in efficacy of the vaccine. This STTR Phase 1 proposal involves the development and characterization of a unique vaccine platform that has been developed by the company POP BIO. This platform consists of fabricating lipid bilayer nanoliposomes with a cobalt-porphyrin moiety intercalated into the bilayer (CoPoP) along with the synthetic monophosphoryl lipid A (PHAD), a TLR4-based vaccine adjuvant. This prep is then combined with his-tagged recombinant influenza HA. The his-tag stably inserts into the bilayer by association with the cobalt producing nanoliposomes decorated with the immunogenic influenza antigen. The CoPoP/PHAD can be mass produced and stockpiled and the production of the influenza HA antigens can be performed rapidly using standard molecular biology techniques (avoiding the long duration of egg production). At the time of vaccination, the recently produced HA antigens can be added on-site to the CoPoP/PHAD vial to produce the vaccine dose. Shortening the time from HA antigen design to time of vaccination will reduce the probability of virus mutation and thus be more effective. In addition, it has been shown that this platform allows for the use of much less antigen in the vaccine (antigen sparing) and has the capacity for multiplexing with numerous antigens from different influenza strains (expanding its breadth). This study will involve POP BIO producing and characterizing the physical and chemical properties of the CoPoP/PHAD-influenza antigen formulations. The University at Buffalo sub-contracting laboratory will then test them in mice to assess the level of protection against challenge with mouse-adapted strains of influenza. The amount of antigen-sparing will be determined in comparison with other influenza vaccine formulations. In addition, the ability of the CoPoP/PHAD nanoliposomes to accommodate multiple different influenza antigens with associated protection against influenza infection in mice will be assessed. The subsequent STTR Phase 2 proposal will expand development of this platform to novel influenza antigen designs and testing in ferrets in preparation for an IND application.